Gas generator assembly

ABSTRACT

A gas generator assembly comprising a housing containing an oxygen evolving cartridge in spaced relation to the housing. A manually operable actuating mechanism, easily reset or cocked by hand, is releasably secured in the housing in spaced relation to the cartridge for igniting the oxygen candle therein. A safety release pin locks the actuating mechanism in the cocked position to prevent inadvertent ignition of the candle.

United States Patent 1191 1111 3,881,394

Netteland May 6, 1975 GAS GENERATOR ASSEMBLY 2,717,042 9/1955 Grant, Jr.et a1. 89 1 B 3,208,177 9/1965 B 42 70 R [75] Inventor: & Netteland EastAurora 3,580,250 5 1971 01:23 23 281 x Assignee= A-T-0In9-,Wil19ughby,Ohio Primary Examiner-Verlin R. Pendegrass [22] Filed; Man 29, 1973Attorney, Agent, or FirmChristel & Bean Appl. No.: 345,992

Related US. Application Data [62] Division of Ser. No. 180,558, Sept.15, 1971, Pat.

[52] US. Cl. 89/1 B; 128/203 [51] Int. Cl A62b 7/08 [58] Field of Search23/281; 89/1 B; 42/70; 102/8; 128/203 [56] References Cited UNITEDSTATES PATENTS 2,376,332 5/1945 Adelman 102/8 X [57] ABSTRACT A gasgenerator assembly comprising a housing containing an oxygen evolvingcartridge in spaced relation to the housing. A manually operableactuating mechanism, easily reset or cocked by hand, is releasably secured in the housing in spaced relation to the cartridge for ignitingthe oxygen candle therein. A safety release pin locks the actuatingmechanism in the cocked position to prevent inadvertent ignition of thecandle.

9 Claims, 9 Drawing Figures PATENTEBHAY 6697:? 3,881,394

SHEET 2 BF 4 GAS GENERATOR ASSEMBLY CROSS REFERENCE TO A RELATEDAPPLICATION This application is a division of pending application Ser.No. 180,558, filed Sept. 15, 1971, now US. Pat. No. 3,756,785.

BACKGROUND OF THE INVENTION This invention relates to a gas generatorand, more particularly, to a self contained oxygenevolving apparatusespecially adapted for regular use by patients having respiratoryailments and for respiratory and cardiac emergencies.

Gas generators comprising oxygen evolving chlorate candles mounted incannisters or containers are known, and offer certain advantages overcylinders of oxygen under pressure. Often, these known generators employan over-the-center type of percussion actuator, which not only isdifficult to cock for repeated action, but requires locating the primerin close proximity to the actuator. Since the heat of combustion of theprimer and candle is intense, the actuator and container reach excessivetemperature. While such oxygen evolving generators are very useful inmany emergency situations, such as might be encountered in submergedwatercraft or high flying aircraft, they present a problem when used byrespiratory patients or by medical personnel whose handle suchgenerators and trigger the actuator by hand. Also, the difficulty inmanually resetting or cocking the actuator for subsequent use with afreshly replaced oxygen candle renders them unsuit' able for repeatedusage by respiratory patients and by medical personnel.-

SUMMARY OF THE INVENTION Accordingly, it is an object of the presentinvention to provide an improved solid state gas generator assemblyhaving a novel actuator that can be easily reset for repeated usage.

It is another object of this invention to provide the foregoing gasgenerator assembly with an actuator arrangement facilitating an optimaldesign relation between the primer and candle body and between thegenerator and the operator.

It is a further object of the present invention to provide a novel solidstate gas generator housing having spaced heat dissipating and heatshielding means to preclude undesirable heat transmission to thehousing.

It is still another object of this invention to provide the foregoinggas generator assembly with a self contained chemical oxygen evolvingunit having means affixed to the opposite ends thereof for properlyorienting such unit in a spaced relation to the actuator and theassociated housing.

In one aspect thereof. the gas generator assembly of the presentinvention is characterized by the provision of stud means affixed to theopposite ends of an oxygen evolving cartridge for spacing the latterfrom the ignition actuating mechanism and from the housing walls. Theignition actuating mechanism is easily operated and reset by hand and isprovided with a locking mechanism to prevent inadvertent firing. Aninner heat dissipating liner and an outer heat shield spaced therefromare interposed between the oxygen evolving cartridge and the housing.

The foregoing and other objects, advantages and characterizing featuresof the present invention will become clearly apparent from the ensuingdetailed description of an illustrative embodiment thereof, takentogether with the accompanying drawing wherein like reference numeralsdenote like parts throughout.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal sectionalview of one form of a gas generating assembly of the present invention;

FIG. 2 is a longitudinal sectional view of another form of gasgenerating assembly of this invention;

FIG. 3 is a fragmentary vertical sectional view, on an enlarged scale,showing the oxygen evolving unit and a portion of the ignition mechanismtherefor;

FIG. 4 is a fragmentary vertical sectional view, on an enlarged scale,showing details of the ignition actuating mechanism in its locked,cocked position;

FIG. 5 is a transverse cross sectional view taken about on line 55 ofFIG. 4;

FIG. 6 is a view similar to FIG. 4, showing the ignition actuatingmechanism in its released, firing position;

FIG. 7 is a transverse cross sectional view taken about on line 7-7 ofFIG. 6;

FIG. 8 is a transverse cross sectional view taken about on line 88 ofFIG. 6; and

FIG. 9 is a transverse cross sectional view taken about on line 99 ofFIG. 6.

DETAILED DESCRIPTION OF AN ILLUSTRATIVE EMBODIMENT Referring now indetail to the drawings, there is shown in FIG. 1 an illustrativeembodiment of an oxygen generator assembly, generally designated 10,constructed in accordance with this invention, comprising a housing 12for enclosing an oxygen generator cartridge 14. Housing 12 is of agenerally cylindrical configuration and comprises a cylindrical tubularshell 16, a bottom end wall 18 having perforations 19 therethrough, anda top end cover 20. Cover 20 is releasably secured to shell 16 by anysuitable means, such as a pair of conventional toggle-type safety locks21 for example. A strap 22 is connected to shell 16 by means of suitablefasteners 23 and is adapted to be looped over the head and about theneck of the user for supporting generator 10 preferably adjacent oneside of the user in the area of the hip region. The terms top, bottom,upper, lower and the like are used for convenience of description withreference to the drawings and are not used in a limiting sense.

As shown in FIG. 3, oxygen generating cartridge 14 comprises a cannister24 encasing an inner body composition capable of evolving oxygen uponburning. By way of example, the composition can consist of aconsolidated core body, hereinafter referred to as an oxy gen candle 26,having uniformly distributed therethrough an alkali metal chlorate orperchlorate which generates oxygen, a finely divided oxidizable materialsuch as iron powder for burning and supplying part of the heat neededfor relase of oxygen through an exothermic reaction, a binder such asinorganic glass fibers or steel wool for holding the mass together andaiding in the even decomposition of the chlorate or perchlorate, andbarium peroxide or like chlorine fixes for chemically eliminating tracesof chlorine gas released during thermal breakdown of the chlorate orperchlorate. Such oxygen candle compositions are known and,

per se, form no part of the present invention. The body of oxygen candle26 can be press-molded or cast to form a cylinder having an ignitionarea located centrally at the upper end thereof, such ignition areacomprising the foregoing composition enriched with a metal powder, suchas iron, to provide a concentrated area of intense heat when ignited.

Candle body 26 is encased within a heat insulating envelope 28 of filtermedium interposed between candle body 26 and cannister 24 to insulatethe latter from the heat of combustion. Envelope 28 can be formed offiberglass and, if desired, impregnated with a silicate or otherhardening agent in an amount sufficient to make the envelope shapesustaining in the desired form. In the illustrative embodiment depictedin FIG. 3, an annular pad 30 is mounted on top of candle 26 and envelope28 in spaced relation to the top end wall 32 of cannister 24. Afiberchrome filter 31 is interposed between pad 30 and cannister top endwall 32. The bottom end of candle 26 is provided with a fiberfrax disc33 having an inwardly dished portion resting on the complementaryinwardly dished portion of a perforated baffle plate 34 supported on ametallic screen 35. A layer of catalyst 36, such as the well knownHopcalite, is sandwiched between a pair of fiberfrax discs 37 beneathoxygen candle 26 and is effective to oxidize to carbon dioxide anycarbon monoxide that may result from the combustion of oxygen candle 26.The lower disc 37 is supported on a micro quartz pad 38 which, in turn,is supported on a fiberglass pad 39 resting on a metallic screen 40.Screen 40 rests against the inner surface of a cannister cover or bottomend wall 41, which is provided with an inturned, curved flange 42 at themarginal edge thereof rolled into sealing relation with an annular bead44 forming a continuation of the cannister body and located at thebottom end thereof. Thus, in forming cartridge 14, the foregoingcomponents are inserted through the bottom open end of cannister 24 andthen sealed by cover 41.

Bottom end wall 41 is formed with an outwardly dished portion 46defining a chamber 48 into which filtered oxygen is collected. A stud,generally designated 50 and having a bore 52 therein, is suitablyattached to portion 46 of bottom wall 41 and is maintained in a gastight relation therewith by means of a suitable seal 54. Stud 50 isprovided with an annular abutment shoulder 56 and a tubular body 58adapted to be received in a manifold coupling as will hereinafter becomeapparent.

Mounted on upper end wall 32 of cannister 24 in a gas tight relationtherewith is a stud 60 having a flange 62 and a cylindrical body 64extending downwardly from flange 62 to pad 30, which is provided with acentral opening communicating with candle 26. A primer 66 is mountedwithin body 64 and communicates with the ignition area of oxygen candle26 through a bore 67 provided in body 64. Stud 60 also includes atubular body portion 68 extending upwardly from flange 62 and having anannular flange 70 spaced from flange 62. Body portion 68 is adapted tobe received in a retainer forming part of the primer actuating mechanismand is bored as at 72 to receive a firing pin, hereinafter more fullydescribed. The oxygen generating cartridge 14 thus far describedincludes studs 50 and 60 and constitutes a disposable, self-containedunit which, when spent, can be replaced by a fresh unit in housing 12.

A manifold 76 is suitably secured to bottom end wall 18 of housing 12(FIG. 1) as by means of screws 78 and is provided with a longitudinalpassage 80 communicating with a tapped opening 82. One end of passage 80leads to a port having a pressure relief valve 84 suitably threadedtherein. The other end of passage 80 leads to a port 86 connected to acoupling 88 having a hose fitting 89 for connection to a flexibledelivery tube (not shown) connected at its other end to the usual facemask, also not shown. The mask, delivery tube and a fitting connectionwhen not in use, can be stored within cover 20. A fitting 90 is threadedinto tapped opening 82 in a gas tight relation therewith and is providedwith a bore 92 for receiving tubular body 58 of stud 50. A seal 94 isdisposed in a peripheral groove formed in body 58 to provide pressuresealing between body 58 and fitting 90. Fitting 90 is provided with anouter face 96 which serves as a seating surface for shoulder 56 of stud50.

A cavity 98 is formed in manifold 76 in registry with opening 82 forreceiving a check valve 100 therein. Check valve 100 is provided with abeveled resilient sealing surface 102 adapted to engage a beveled valveseat 104 formed on the end of fitting 90. Valve 100 is normally biasedagainst valve seat 104 by means of a helical spring 106 disposed betweenthe rear face of valve 100 and the bottom of cavity 98. The filteredoxygen under pressure generated by the combustion of candle 26 flowsfrom chamber 48 through bore 52 of stud 50 and acts against valve 100 tourge the latter away from its seat 104, allowing the oxygen to flowthrough opening 82, passage 80, port 86, coupling 88 and ultimately tothe user. Excess pressures are dissipated through relief valve 84 in theuaual manner.

A support plate 1 10 is mounted within the lower end of housing 12(FIG. 1) between manifold 76 and a stepped flange on fitting 90. Plate110 has a generally circular planar portion 112 and an offset ledge 114connected to portion 112 by an annular shoulder 116 and terminating inan annular flange 118. Plate 110 supports the lower ends of a pair ofconcentric, cylindrical lines 120 and 122 the inner liner 120 beingmounted in spaced relation to cartridge 14 and perforated as at 124 fordissipating the heat generated by the combustion of candle 26. The lowerend of liner 120 is supported on the planar portion 112 of plate 110against shoulder 116. Outer liner 122, which serves as a heat shield, isspaced radially from liner 120 and is supported at its lower end onledge 114 against flange 118. The upper ends of liners 120 and 122 aresupported in spaced relation by means of a retainer member 126 bonded orotherwise fixedly secured to the upper end of housing shell 16. Member126 has spaced cylindrical partitions 128 and 130 for embracing theupper ends of liners 120 and 122. A plurality of passages 132 areprovided in member 126 and connect an annular passage 134 definedbetween liners 120 and 122 to the ambient atmosphere when cover 20 isremoved from shell 16. Heat is dissipated during combustion of candle 26by convection through the perforated liner 120 and upwardly throughpassages 134 and 132 to the ambient atmosphere. Liner 122 serves as aheat shield retaining the heat within passage 134 and preventing thetransmission of heat to housing 12 thereby protecting the user againstburning contact with housing 12. Member 126 is provided with a centraltapped opening 138 for receiving a cup-shaped casing 140 threadablysecured therein and provided with a bottom wall 142 for supporting anignition actuating assembly,

generally designated 144 (FIG. 4). Bottom wall 142 is provided with aplurality of openings 143 connecting the area within liner 120 with theambient atmosphere to aid in the dissipation of heat generated by candle26 during combustion.

As best shown in FIGS. 4-8, actuating assembly 144 comprises a retainer146 having a flange 148 engaging against the underside of bottom wall142 and a body portion 149 threadably secured to an actuator 150.Retainer 146 has a bore 152 therein for receiving the upper portion oftubular body 68 of stud (FIG. 3) and a firing pin 154 having an axialprojection 156 adapted to strike primer 66 for firing the latter. Flange148 is provided with an annular rib 158 of generally triangular crosssection having an annular apex portion 160 adapted to seat against studflange (FIG. 3) of cartridge 14 for properly locating the parts in theassembled relation. The entire actuating assembly 144 is assembled as aunit to cartridge 14 by inserting the upper end of stud 60 into bore 152of retainer 146 and then threading casing into opening 138 of member 126until rib 158 seats against flange 70. Bore 72 of stud 60 is coaxiallyaligned with bore 152 of retainer 146 for receiving the end portion offiring pin 154 in the assembled relation with the upper portion oftubular body 68 interposed between retainer 146 and firing pin 154.

Actuator comprises a generally cylindrical body 164 having an end wall166 provided with a central opening 168 therein. Body 164 is providedwith four circumferentially spaced openings 170 for receiving balls 172as shown in FIG. 8. Of course, more or less than four openings 170 and acorresponding number of balls 172 can be provided, as desired. Body 164is provided with a reduced diameter portion 174 and a further reduceddiameter portion 176 separated by a beveled shoulder 178 for a purposehereinafter explained. An insulator cap 180 is mounted on the upper endof body 164 about end wall 166 and is provided with an annular bead 182received in a peripheral groove formed in body 164.

Firing pin 154 is provided with a cup-shaped member 184 formed integraltherewith and telescopically received within actuator body 164. Member184 is provided with openings 186 adjacent firing pin 154 to permit theheat of candle 26 to escape by convection. A compression spring 188 ismounted within member 184 for biasing firing pin 154 toward primer 66.Member 184 is provided with a peripheral groove 190 having a beveled camsurface 192 extending from groove 190 to the outer peripheral surface ofmember 184. Groove 190 receives portions of balls 172 when aligned withopenings 170 of actuator 150 as shown in FIG. 4 and cam surface 192 aidsin ejecting balls 172 out of groove 190 upon downward movement of member184 relative to actuator 150.

An actuator sleeve 196 is mounted about actuator 150 for slidingmovement relative thereto and comprises a hollow body 198 having aninner wall surface 199 and formed with an elongated enlargement 200(FIG. 5) at one side thereof extending generally normal to the axis ofbody 198. As shown in FIG. 9, a portion of the inner wall surface ofbody 198 is flat sided as at and complementary to a flat side portion197 of actuator body 164 to prevent relative rotation therebetween.Thus, bodies 164 and 198 can move axially relative to each other but arekeyed against relative rotational movement. The inner wall surface 199of the upper portion of sleeve body 198 is provided with an annularbeveled shoulder or cam surface 201 leading to an enlarged insidediameter portion 203. The lower portion of body 198 is provided with anenlarged cupshaped configuration having a cylindrical wall 202 radiallyspaced from actuator body 164 for receiving a compression spring 204therein. The lower end of spring 204 abuts against a washer 206supported between casing bottom wall 142 and an annular shoulder 208provided adjacent the lower end of actuator body 164.

Enlargement 200 is provided with axially aligned bores 210 for receivingan elongated safety lock shaft 212, the central portion of which passesbetween portion 202 of sleeve body 198 and portions of the outerperipheral surface of actuator body 164. Enlarged heads 214 are securedto the opposite ends of shaft 212 as by means of suitable fasteners 216.These heads 214 are adapted to be received in cavities 218 provided atthe opposite ends of enlargement 200. Shaft 212 is provided with anintermediate reduced diameter portion 220 having annular, bevelledshoulders or cam surfaces 222 leading to the outer peripheral surface ofshaft 212. Shaft 212 is adapted to be shifted axially into a lockedposition as shown in FIGS. 4 and 5 whereby actuator sleeve 196 andactuator body 164 are keyed to gether and into a release position asshown in FIG. 7 whereby sleeve 196 can be moved vertically relative toactuator body 164.

Prior to use, the various components of actuating assembly 144 are inthe relative positions shown in FIGS. 4 and 5 with safety lock shaft 212captively held between portion 203 of actuator sleeve 196 and thereduced diameter portion 176 of actuator body 164. Thus, actuator sleeve196 and body 164 are keyed together preventing relative sliding movementtherebetween. Also, balls 172 are captively disposed in openings 170 ofactuator body 164 and partially in peripheral groove 190 of member 184.In this position, balls 172 lock member 184 upwardly against the bias ofspring 188, thus maintaining firing pin 154 upwardly within bore 152 ina cocked position.

In use, strap 22 is placed about the users neck region in a mannersupporting generator 10 along one side of the user and the toggle-typesafety locks 21 are re leased. Cover 20 can then be removed from housing12 and the breathing mask and delivery tube removed and connected tocoupling 89. The breathing mask is not placed about the users mouthuntil the oxygen generator is actuated and the oxygen evolving processinitiated. Cover 20 is left dangling from generator 10 by means of atether strap 226 connected at one end thereof to a central boss 228 inend cover 20 by a fastener 230 (FIG. 1) and connected at the other endto member 126 by any suitable means (not shown). Thus, although cover 20is removed from housing 12 to expose actuating assembly 144, it remainsattached thereto by strap 226 so as to prevent misplacement thereof.

The user then shifts safety llock shaft 212 axially to position thereduced diameter portion 220 between portion 203 of actuator sleeve 196and portion 176 to actuator body 164 to permit actuation of assembly144. To initiate the oxygen evolving process, actuator sleeve 196 isslid downwardly relative to body 164 against the bias of spring 204 tothe position shown in FIG. 6. This relative movement can be effected dueto the reduced diameter portion 220 of shaft 212 which readily fits intothe space between portion 203 of sleeve 196 and portion 174 of body 164.

Upon relative sliding movement between sleeve 196 and body 164, thelarger inside diameter portion 203 of sleeve 196 provides a wider spacefor receiving balls 172 which are cammed radially outwardly from grooves190 by cam surface 192 under the influence of spring 188. Member 184 isthereby released allowing the force of spring 188 compressed therein todrive firing pin 154 downwardly into contact with primer 66 for ignitingthe latter and initiating ignition of oxygen candle 26. When firing pin154 is released, the various components of actuating assembly 144 are inthe relative positions shown in FIG. 6. The evolved oxygen passesthrough chamber 48, bore 52 of stud 50 and bore 92 of fitting 90. Thepressure of the evolved oxygen builds up and acts against the face ofcheck valve 100 until such pressure overcomes the bias of spring 106 tounseat valve 100. The oxygen excapes past check valve 100, throughpassage 80, port 86, coupling 88, hose fitting 89 and the delivery tubeto the face mask at a rate sufficient to meet the oxygen consumption ofthe user. Excess pressures are relieved through valve 84.

The heat generated by the combustion of oxygen candle 26 is dissipatedby convection through perforated liner 120, passage 134, 132 andoutwardly through the open end of housing 12 into the ambientatmosphere. Perforations 19 in bottom end wall 18 permit cool air tocommunicate with the interior of housing 12 to ventilate the latter andfacilitate such heat dissipation. Any heat transmitted upwardly isdissipated through openings 143 in member 126 and through retainer bore152, openings 186, the interior of cupshaped member 184, and outwardlythrough aligned openings in end wall 166 and cap member 180. Outer liner122 serves as a heat shield and aids in directing the heat upwardlythrough passage 134. Housing wall 16, which is spaced from liner 122, isvirtually uneffected by the intense heat generated by oxygen candle 26,which heat is dissipated outwardly through perforated liner 120 andupwardly by convection through the open end of housing 12. Also, thesuspension of cartridge 14 within housing 12 at only two points by meansof studs 50 and 60 significantly contributes to the dissipation of heataway from housing 12. As a result, the temperature of housing shell 16remains low and is harmless against human contact therewith. This isespecially significant when it is realized that cannister 24 maintains atemperature of approximately 400F during normal combustion of thecandle.

The size and the oxygen evolving duration of cartridge 14 can vary, asdesired. Also, oxygen candle 26 can be of the muIti-stage ignition typeproviding full flow operation at the mask within a predetermined minimaltime limit and providing a minimum rate of relatively high oxygen flowfor the first few minutes followed by a smooth transition to a minimumrate of reduced oxygen flow for the remainder of the oxygen evolvingduration. However, once candle 26 is ignited, it will continue to burnuntil expended.

In order to replace a spent cartridge 14 with a fresh one and to resetactuating assembly 144 for subsequent operation, cover 20 -is removedand casing 140 is threaded out of retainer member 126, carrying with itthe entire ignition actuating assembly 146 to expose cartridge 14. Tofacilitate the removal of a spent cartridge 14, a tool 234 (FIG. 1) isreleasably mounted in cover 20 as by means of a spring clip 236 fixed tofastener 230.

Tool 234 comprises a strip 236 of metal reversely bent to form a loop238 which serves as a handle for tool 234. The reversely bent portion isspaced from the main strip portion by a spacer element 240 and isconnected thereto by means of a suitable fastener 242. The distal end oftool 234 is bent inwardly as at 244 and is bifurcated to provide spacedfingers 246 (only one of which is shown in FIG. 1) adapted to engageabout body portion 68 of stud 60 below flange 70. The angular bend 244in tool'234 facilitates the entry of fingers 246 into opening 138 ofretainer member 126 and the positioning thereof about stud 60 so as toapply upward pressure against flange 70 and raise cartridge 14 out ofhousing 12. A fresh cartridge 14 can then be placed in housing 12 withtubular body 58 of stud 50 inserted Within fitting until shoulder 56abuts against face 96 of fitting 90. Thus, cartridge 14 is correctlypositioned within housing 12 in readiness to receive actuating assembly144, which must be reset and cocked prior to assembly with cartridge 14.

When actuating assembly 144 is detached from retainer member 126, thevarious parts thereof are in the relative positions shown in FIG. 6. Inorder to reset or cook actuating assembly 144, firing pin 154 is forcedwithin actuator body against the bias of spring 188. When groove 190 isaligned with openings in body 150, balls 172 will be shifted inwardly bycam surface 201 actuator sleeve 196 under the influence of spring 204.Actuator sleeve 196 is then free to move upwardly relative to body 150under the urging of spring 204, carrying safety lock shaft 212therewith. The various parts of actuating assembly 144 are then in therelative positions illustrated in FIG. 4 and firing pin 154 is held inits cocked position by means of balls 172. Lock shaft 212 is shiftedaxially to lock actuating sleeve 196 in its raised position to preventinadvertent release of firing pin 154. Casing 140, together withactuating assembly 146 in its cocked position, can then be assembled toretainer member 126 and cartridge 14 in a manner hereinbefore described.

FIG. 2 illustrates another form of an oxygen generator assembly of thisinvention which is similar to the form of the invention first describedexcept that the housing, identified by numeral 12, is made larger tocontain two cartridges 14, which may be serially activated to produce asubstantially continuous flow of oxygen when one of the cartridges I4 isspent. As shown in FIG. 2, manifold 76' is substantially longer thanmanifold 76 to receive the output of both cartridges l4. Retainer member126' also is different in construction in order to accommodate bothcartridges l4 and their actuating assemblies 144. However, eachcartridge 14 is provided with its own inner and outer liners, 120 and122, respectively, in a construction similar to that first described.FIG. 2 also illustrates the use of a fastener 250 fixed to member 126'for securing the other end of tether strap 226 thereto preventingcomplete detachment of cover 20 and possible misplacement thereof. Theother elements shown in FIG. 2 are identical to those described inconnection with the first form of the invention and are identified bysimilar reference characters.

An advantage residing in the second form of this invention is that thesecond cartridge can be ignited just prior to the depletion of the firstto provide a continuous flow of oxygen to the user, if required. Whilethe second cartridge is being consumed, the first can be replaced bystill another cartridge to insure a continuous supply, when needed. Ofcourse, the present invention contemplates the use of any number ofcartridges l4 suitably mounted in a common housing, as desired.

From the foregoing, it is apparent that the'objects of the presentinvention have been fully accomplished. As a result of this invention,an oxygen generator is mounted within a housing in spaced relationthereto and is provided with means for dissipating the heat releasedfrom the burning generator by convection away from the housing to enablethe latter to be safely handled by the user during combustion. An easilycocked, manually operable actuating mechanism is releasably mounted inthe housing in spaced relation to the generator to prevent overheatingof the actuator.

Certain embodiments of this invention having been described andillustrated in detail, it is to be understood that this has been done byway of illustration only.

I claim:

1. In combination with oxygen evolving apparatus adapted to be carriedwith the user; a manually operable actuating mechanism for igniting anoxygen evolving candle in said apparatus comprising: a casing; a retainer mounted in said casing adapted for connection to a cartridgecontaining an oxygen evolving candle, an actuator body mounted in saidcasing, said actuator body having adjacent peripheral surface portionsof different dimensions, a firing pin mounted in said actuator body andmovable from a cocked position to a firing position, means biasing saidfiring pin to said firing position, means retaining said firing pin insaid cocked position against said biasing means, means for disablingsaid retaining means enabling said firing pin to move to said firingposition, said disabling means comprising an element movably mounted onsaid actuator body for movement between a first position where saidretaining means maintains said firing pin in said cocked position to asecond position disabling said retaining means, and means locking saiddisabling means to prevent actuation of said firing pin into said firingposition, said locking means comprising an elongated element havingadjacent portions of different cross section and mounted in saiddisabling element for movement between a locked position wherein saidlocking element engages said actuator body on the periphery thereof withone of said portions of said locking element engaging one of saidperipheral surface portions of said actuator body in a manner preventingrelative movement between said disabling element and actuator body and arelease position wherein said locking element is disengaged from theperiphery of said actuator body in a manner allowing relative movementbetween said disabling element and actuator body.

2. An actuating mechanism according to claim 1 wherein said retainingmeans includes an extension on said firing pin provided with an annulargroove, 21 plurality of openings in said actuator body, and means keyingsaid firing pin extension to said tubular body when said openings are inregistry with said groove.

3. An actuating mechanism according to claim 2 wherein said disablingmeans comprises a sleeve slidable relative to said actuator body andhaving an enlarged inner diameter portion enabling said keying means tobe displaced from said groove in said actuator to permit said firing pinto be driven by said biasing means.

4. An actuating mechanism according to claim 1 wherein said lockingmeans comprises an elongated shaft having a reduced diameter portionmovable between a position locking said disabling means and a positionrelasing said disabling means.

5. An actuating mechanism for igniting an oxygen evolving candlecomprising: a casing; a retainer mounted in said casing adapted forconnection to a car tridge containing and oxygen evolving candle, anactuator body mounted in said casing, a firing pin mounted in saidactuator body and movable from a cocked position to a firing position,means biasing said firing pin to said firing position, means retainingsaid firing pin in said cocked position against said biasing means,means for disabling said retaining means enabling said firing pin tomove to said firing position and locking means comprising shaft meansmovably connected to said disabling means in a manner permitting limitedaxial movement of said shaft means, said shaft means having differentdiameter portions between the ends thereof and a pair of stop membersspaced axially from said different diameter portions for abutting saiddisabling means to limit the axial movement of said shaft means betweentwo positions, said shaft means being manually shiftable from a lockedposition engaging said actuator body wherein said actuator body and saiddisabling means are keyed together to a release position disengaged fromsaid actuator body whereby said disabling mean can be moved relative tosaid actuator body, said stop members limiting the axial movement ofsaid shaft means between said locked position and said release position.

6. An actuating mechanism according to claim 5 wherein said retainingmeans includes an extension on said firing pin provided with an annulargroove, a plurality of openings in said actuator body, and means keyingsaid firing pin extension to said tubular body when said openings are inregistry with said groove.

7. An actuating mechanism according to claim 6 wherein said keying meanscomprises a plurality of ball members partially disposed in saidactuator body openings and partially disposed in said extension groovefor maintaining said firing pin in said cocked position.

8. An actuating mechanism according to claim 6 wherein said disablingmeans comprises a sleeve slidable relative to said actuator body andhaving an enlarged inner diameter portion enabling said keying means tobe displaced from said groove in said exten sion to permit said firingpin to be driven by said biasing means.

9. An actuating mechanism according to claim 8 including an elongatedshaft having a reduced diameter portion, said actuator body having areduced diameter portion, said shaft being movable into a position aligning the full diameter portion of said shaft with said reduced diameterportion of said actuator body to lock said disabling means and aposition aligning said shaft reduced diameter portion with said bodyreduced diameter portion to release said disabling means.

f =i= l UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION ,PATENTNO. 3 l 394 DATED I May 6, 1975 INVENTOR(S) Loyal G. Netteland It iscertified that error appears in the above-identified patent and thatsaid Letters Patent are hereby corrected as shown below:

Claim 4, Line 5, "relasing" should be changed to -releasing- Claim 5,Line 4, "and oxygen" should be changed to an oxygen-.

Signed and Sealed this twen ty-eight D 3y Of October 1 975 [SEAL] Attest:

RUTH C. MASON C. MARSHALL DANN Arresting Office? Commissioner ofPaIentsand Trademarks UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTIONPAIENTNO: 4

DATED May 6, 1975 INVENTOWS) 3 Loyal G. Netteland It is certified thaterror appears in the above-identified patent and that said LettersPatent are hereby corrected as shown below:

Claim 4, Line 5, "relasing" should be changed to releasing- Claim 5,Line 4, "and oxygen" should be changed to --an oxygen-.

Signed and Sealed this twenty-eight Day of October 197;

[SIZAL] Arrest:

RUTH C. MASON C. MARSHALL DANN Arresting Offiz-er (rrmmissioner ofParents and Trademarks

1. In combination with oxygen evolving apparatus adapted to be carriedwith the user; a manually operable actuating mechanism for igniting anoxygen evolving candle in said apparatus comprising: a casing; aretainer mounted in said casing adapted for connection to a cartridgecontaining an oxygen evolving candle, an actuator body mounted in saidcasing, said actuator body having adjacent peripheral surface portionsof different dimensions, a firing pin mounted in said actuator body andmovable from a cocked position to a firing position, means biasing saidfiring pin to said firing position, means retaining said firing pin insaid cocked position against said biasing means, means for disablingsaid retaining means enabling said firing pin to move to said firingposition, said disabling means comprising an element movably mounted onsaid actuator body for movement between a first position where saidretaining means maintains said firing pin in said cocked position to asecond position disabling said retaining means, and means locking saiddisabling means to prevent actuation of said firing pin into said firingposition, said locking means comprising an elongated element havingadjacent portions of different cross section and mounted in saiddisabling element for movement between a locked position wherein saidlocking element engages said actuator body on the periphery thereof withone of said portions of said locking element engaging one of saidperipheral surface portions of said actuator body in a manner preventingrelative movement between said disabling element and actuator body and arelease position wherein said locking element is disengaged from theperiphery of said actuator body in a manner allowing relative movementbetween said disabling element and actuator body.
 2. An actuatingmechanism according to claim 1 wherein said retaining means includes anextension on said firing pin provided with an annular groove, aplurality of openings in said actuator body, and means keying saidfiring pin extension to said tubular body when said openings are inregistry with said groove.
 3. An actuating mechanism according to claim2 wherein said disabling means comprises a sleeve slidable relative tosaid actuator body and having an enlarged inner diameter portionenabling said keying means to be displaced from said groove in saidactuator to permit said firing pin to be driven by said biasing means.4. An actuating mechanism according to claim 1 wherein said lockingmeans comprises an elongated shaft having a reduced diameter portionmovable between a position locking said disabling means and a positionrelasing said disabling means.
 5. An actuating mechanism for igniting anoxygen evolving candle comprising: a casing; a retainer mounted in saidcasing adapted for connection to a cartridge containing and oxygenevolving candle, an actuator body mounted in said casing, a firing pinmounted in said actuator body and movable from a cocked position to afiring position, means biasing said firing pin to said firing position,means retaining said firing pin in said cocked position against saidbiasing means, means for disabling said retaining means enabling saidfiring pin to move to said firing position and locking means comprisingshaft means movably connected to said disabling means in a mannerpermitting limited axial movement of said shaft means, said shaft meanshaving different diameter portions between the ends thereof and a pairof stop members spaced axially from said different diameter portions forabutting said disabling means to limit the axial movement of said shaftmeans between two positions, said shaft means being manually shiftablefrom a locked position engaging said actuator body wherein said actuatorbody and said disabling means are keyed together to a release positiondisengaged from said actuator body whereby said disabling mean can bemoved relative to said actuator body, said stop members limiting theaxial movement of said shaft means between said locked position and saidrelease position.
 6. An actuating mechanism according to claim 5 whereinsaid retaining means includes an extension on said firing pin providedwith an annular groove, a plurality of openings in said actuator body,and means keying said firing pin extension to said tubular body whensaid openings are in registry with said groove.
 7. An actuatingmechanism according to claim 6 wherein said keying means comprises aplurality of ball members partially disposed in said actuator bodyopenings and partially disposed in said extension groove for maintainingsaid firing pin in said cocked position.
 8. An actuating mechanismaccording to claim 6 wherein said disabling means comprises a sleeveslidable relative to said actuator body and having an enlarged innerdiameter portion enabling said keying means to be displaced from saidgroove in said extension to permit said firing pin to be driven by saidbiasing means.
 9. An actuating mechanism according to claim 8 includingan elongated shaft having a reduced diameter portion, said actuator bodyhaving a reduced diameter portion, said shaft being movable into aposition aligning the full diameter portion of said shaft with saidreduced diameter portion of said actuator body to lock said disablingmeans and a position aligning said shaft reduced diameter portion withsaid body reduced diameter portion to release said disabling means.